[HBR] WARC bands?

[Walt Hutchens]

Brian said:

> I'm wondering whether there is a way to stretch 15m and 10m coverage
> to include 17m and 12m.

The thing you get into is that any ham band only receiver that does it
directly (the 1st LO is tuned to cover the band) is going to have a
very small tuning cap -- 10-15 mmf maximum or something like that. The
delta-c as a percentage of the total capacitance varies as the square
of the delta-f. (The square is double the percentage, for small
bands.) So you get down to VERY small fixed capacitance values very
quickly when you try to cover bigger bands and that gives you assorted
unpleasant problems.

80 is the widest band for the standard coil set -- 12.5% of the top
end of the band. Bands that are smaller are doable, those that are
larger, not so much.

Walt
KJ4KV